1. Field of the Invention
This invention relates to a communication module and a communication apparatus, and specifically, the communication module is used in the communication connected by plural rated communication modules, and transmits and receives with the rated communication modules and plural external apparatuses.
2. Description of the Related Art
A communication apparatus such as an Ethernet® switch (hereinafter, an “etherswitch”) includes an LSI for packet switching, a controller and software therefor, and a communication interface. A part of the interface of the etherswitch, which depends on a physical characteristic of a communication path (e.g., using an optical signal, using an electric signal), is formed by the rated communication module which is modularized, and may be selected according to needs such as a transmission distance.
In recent years, especially in a field of an optical communication, a pluggable module which can be easily put on and taken off the apparatus is commonly used so as to select the transmission distance and a transmission media even after the communication apparatus is set in a base station or a building. The pluggable module is defined as an industry standard called MSA (Multi Source Agreement), and by complying with the standard, the communication module of a supplier having many users can be used freely.
A conventional common communication apparatus includes a plurality of apparatus side signal processing circuits for processing a communication signal which is transmitted to and received from a plurality of the rated communication modules (e.g., rated optical transceiver) with a predetermined communication speed which is connected to the communication apparatus, and a switch LSI for switching these apparatus side signal processing circuits.
The related arts of the invention are, for example, JP-A-2003-502691, JA-A-2004-104706, and JP-A-2004-112775.
However, since the conventional communication apparatus basically has one communication module for one port (e.g., a one-to-one correspondence), a port density cannot be increased. Since the number of communication ports is increasing dramatically with an increasing scale of a network, if the communication port density does not increase, many costs, such as an apparatus and a setting place increase. However, it is difficult to solve that. Although there is a communication module integrating a plurality of the communication modules, the communication module will be a special module not based on the standard, and further, the port density does not become very high.
Moreover, in the conventional communication, the communication speed cannot be changed by changing the communication module.
For example, when there is a user to need three 10-Gbit/s ports and ten 1-Gbit/s ports, as shown in FIG.5, one 10-Gbit/s communication apparatus 51A and one 1-Gbit/s communication apparatus 51B are prepared. Then, a 10-Gbit/s communication module 53A having a communication port 52 of 10-Gbit/s is connected to the 10-Gbit/s communication apparatus 51A, the communication module 53A, and a communication module 53B connected to the communication apparatus 51B are connected by an optical fiber 54, and network 50 is formed.
Therefore, not only two types of two communication apparatuses 51A and 51B (i.e., 10-Gbit/s and 1-Gbit/s) are necessary, but the expensive communication port 52 of 10-Gbit/s is necessary for connecting the two adjacent communication apparatuses 51A and 51B other than for interfacing to an external apparatus despite a short-distance transmission.
Therefore, prior to the present invention, there has been no conventional system which can provide a communication module and a communication apparatus which can reduce the type and the number of communication apparatuses necessary for forming a network, and can reduce the number of futile (unused) high-speed and short-distance ports.